For John Peterschmidt, Memorial Day is a time to remember the 17 colleagues he saw perish before his eyes four years ago.

The commander of the USS Pickney, which was stationed off the coast of San Francisco on Monday to join in The City’s Memorial Day celebration, was serving in Yemen in 2001 when another Navy ship, the USS Cole, was struck by a small boat carrying explosives, killing 17 Americans.

“I can still see their faces as if it was yesterday, and I will never forget,” he said.

Peterschmidt and the entire crew of the USS Pickney joined hundreds of San Franciscans standing close together on a warm day at the San Francisco National Cemetery in the Presidio for The City’s 138th annual Memorial Day ceremony.

Flags cast their shadows on the marble tombstones of the fallen soldiers as dignitaries led the audience in song, prayer and celebration. Recently returned Iraq war veterans Montgomery Singleton and Shannon Alvarez laid four wreaths on the stage with the numbers 2,759 spread across them to commemorate the number of U.S. soldiers killed in Iraq and Afghanistan. A special commemoration was also made for the women who have died in combat since 9/11.

San Francisco Mayor Gavin Newsom said he runs through the cemetery every day and reflects on the sacrifice made by those who lay there. He paid special tribute to the families of soldiers whose loved ones returned from war changed people, like his own grandfather.

“I never had the honor to spend a lot of time with him,” he said. “He came back after years of internment a changed man and ultimately took his own life.”

The memorial was an opportunity for young and old veterans, some wearing uniforms dating back to World War II, to come together and remember their shared pasts.

“Today is a somber day as we remember so many who died,” Peterschmidt said. “Today is their day.”

The morning memorial started with a parade to the cemetery and ended with guided tours of the graves.

A ceremony was also held at Cypress Lawn Cemetery in Colma, a 114-year-old cemetery where more than 4,000 soldiers and veterans are buried.